Hello lisa where are you?

Which theme is best supported by the descriptive detail in this passage from my antonia

Me read the letter. dear aunt mary, you for the wonderful painting. you are so talented! i was thrilled that you chose to paint horses. you must have remembered that i was crazy about horses when i was a little kid—and i still love them. i have hung the painting in my room so that i can see it every morning when i wake up. your loving niece, celia what makes this letter appropriate for its intended audience? it is written from the third-person point of view. it is concise and impersonal. its sentence structure is varied. its language is informal.

When mrs. jameson says "it (the desert) won't leave you cold," what does she mean?